Answer:
Step-by-step explanation:
a ) A force of 6 N , causes elongation of .03 m 
Spring constant 
k = 6 / .03
= 200 N / m 
b ) 
Amplitude A = .04 m .
Maximum velocity of a particle in SHM 
= ωA where ω is angular velocity and A is amplitude
= 
 x A
= 
 x A
= 20x .04 = 0.8 
Maximum velocity of a particle 
= 0.8 m ² s 
Minimum velocity will be zero at extreme point ( at turning point )
c ) 
Minimum acceleration is zero at middle point ( equilibrium position )
maximum acceleration 
= ω²A
= k / m x A
= 400 x .04
= 16 m / s 
d ) 
At halfway point velocity will be √ 3 / 2 times the maximum velocity
velocity at mid point 
= √ 3 / 2 x max velocity
.866 x 
 = .866 x 0.8 
= .693 m /s